The 26-year-old picked up a knee injury in training and is expected to be sidelined four to six weeks, potentially ruling him out for the Reds' first three league games.
Adam Lallana will not be rushed back from a knee injury ahead of schedule, according to Liverpool manager Brendan Rodgers.
Liverpool was dealt a major blow when it was confirmed Lallana — a 31 million-euro signing from Southampton — sustained lateral collateral ligament damage during a training session in the United States.
The 26-year-old is expected to miss up to six weeks, putting him in doubt for Liverpool's first three games of the Premier League season against Southampton, champion Manchester City and Tottenham.MORE: Beautiful fans in Brazil | Barcelona's new bright kits | Juve's jerseys
And speaking ahead of Sunday's International Champions Cup fixture against Olympiacos in Chicago, Rodgers told reporters the England international would be given time to recover.
"Of course it was very disappointing — it's probably going to be four to six weeks," Rodgers said at a media conference from Soldier Field in Chicago. "He has looked fantastic in training; it was just a very simple exercise with no pressure. The medical team are looking closely at that at the moment.
"We're hopeful that he'll come back fairly quickly but there's no rush. He's a fantastic player, we just need to get him back fit and well because it's a long season."